Top spinning roll cover



y 1934- J. c. EMHARDT ET AL 1,967,929

TOP SPINNING ROLL COVER Filed Jun 24, 1931 FIG. 1. 2

V wvntow ..TCH-LTL E.. EmhaPd Fr' E :la Pick Mall. MnNair E E [HEE L.. 5 ::hwarTz Patented July 24, 1934 UNITED STATES 1,967,9Z9 PATENT OFFICE Las-1,929 TOP SPINNING ROLL CovEa Application June 24, 1931, Serial No. 546588 3Claims.

This invention relates to covers for the perimeters of top spinning rolls, and more particularly it relates to an improved top spinning roll cover comprising a fabric base coated to produce a smooth surface on one side for the production ot a cover adapted for contact with wool, cotton or other flbrous threads.

Heretofore in spinning mills, the top spinning roll, as used in the manufacture of cotton or wool yarns or threads, has had, as the preferable coverings on the surfaces which bear on the flbres being prepared, a leather cot. As understood by those skilled in the spinning art, the spun thread passes between spaced pairs of rolls, each succeeding pair of rolls having a slightly greater peripheral speed than the preceding pair in order to tension the thread. The core of the roll consists of a steel mandrel of dimensions to suit the machine. The portions of the mandrel to be covered were first covered evenly by a woolen felt, as a cushion, over which cushion was placed a surface covering of leather having a smooth surface. To give Satisfaction in operation, the principal requirements of the covering material were, smooth outside surface of the leather, uniform thickness including the joints, durability, and a certain amount of softness with resilience when pressed.

This invention has as an object the production of a spinning roll cover, rrom a material other than leather, which possesses certain advantages not found in the usual spinning roll covers as will more fully appear in the following speciflcation. Other objects will appear hereinafter.

These objects are accomplished by the following invention which in its more general aspects consists in impregnating flbrous sheet material having the requisite strength and porosity with a suitable impregnating medium in such an amount as will yield a product having the desired pliability, tensile strength, resilience, resistance to abrasion, capability of being smoothly cut diagonally through the surface for cementing into a perfect ring or cot, and having sufllcient porosity after impregnation to enable the cut edges to be cemented or glued together. This impregnated sheet material is then coated with a composition which imparts a smooth dry surface suitable for contact with the flbres.

In the drawing:

Fig. 1 is an elevation of the sheet material properly cut to be formed into a ring. Fig. 2 shows the material formed into a ring. Fig. 3 is an elevational View partly in section of a spinning roll with the covering thereon. Fig. 4 is a view similar to Fig. 3 showing a modification of the invention.

The flbrous material, preferably a felted flbrous sheet or paper impregnated and provided with a suitable coating 2, as will be more speciflcally described hereinafter, is cut diagonally along opposite edges from face to back as indicated at 3 and 4, the bias or diagonal of one cut edge being opposite in direction from that of the other so that the edges may be cemented together, as indicated at 7 in Fig. 2, to form a smooth ring. In Fig. 3 the spinning roll cover formed in this manner is shown applied over the usual cushion of woolen felt 5 surrounding the mandrel 6. The spinning roll cover made in accordance with the present invention may replace both the leather cover and the woolen felt cover as indicated in Fi 4.

In carrying out the invention, we prefer to select a paper or felted fibrous base of about .01 to .05 inch thick which is sufificiently porous to absorb enough impregnating medium to give a strong product which is at the same time pliable and which is still porous enough to permit glueing of the cut edges.

According to the preferred method of practicing the invention, we use as a base fabric a beater type impregnated paper. This is made by preparing cotton shearings in paper machinery 'beaters in the usual manner well known in the art, adding rubber latex in the proportion of 10% to 50% of dry rubber to total dry weight. By rubber latex we means the natural and artificial aqueous dispersions of rubber. With this mixture small amounts of dyestuff or pigments may be added for coloring purposes. The sheet is formed from this dispersion in a standard cylinder type paper making machine and finished with drying drums and calenders. The thickness of this paper may vary from .006 to .045". Its usual density produces a weight of .06 ounce per square foot per .0( )1" thickness. The impregnated sheet is then coated with a composition which imparts a smooth dry surface suitable for contact with the fibres being spun. A suitable composition for this purpose is as follows:

Example I Lbs. Bone black 18 Nitrocellulose 15 Castor oil 18 Alcohol 15 Ethyl acetate 19 Benzol 15 coating.

Example II Lbs. Pyroxylin 12 Alcohol 25 5 Ethyl acetate 38 Benzol 25 After the coatings have been dried by passing the wet coatings through an atmosphere of heated air, the goods are ready to use for top spinning roll coverings or they may be embossed to improve the surface.

various other compositions may be substituted for those mentioned and pig-ments other than carbon or -bone black may be substituted when other colors are desired. Castor oil or other softening agents may be increased or decreased to produce a harder or softer film. The top coating may also be comprised of a pigmented rubber coating composition. Thus, the base material may be coated with a rubber solution by means of doctor knives using the following formula:

Example III Parts by weight Amber crepe 15.5 Litharge 8.0 Sulphur .5 Whiting 26.0 Gasoline 50.0

This coating is dried in the usual way of passing it over heated coils. It is aterwards cured by hanging in an oven heated to preferably 250 F. for two hours. The temperature may vary from 230 F. to 250 F. and time from five hours to one hour.

While the pigments are useful in the top coating for the production of a satisfactory surface, their presence, except in small amounts, is not desirable in the impregnating compositions.

A very porous base material having a high impregnated strength and capable of absorblng large amounts of latex or other impregnating material while retaining a high degree of flexibility and residual porosity to permit gluelng may be made as follows: Wood or other suitable fibrous cellulose pulp prepared by any suitable Chemical process for producing pulp, is treated at room temperature with sodium hydroxide of 8 to concentration in the ratio of about 4.5 to 7.4 parts by weight of liquor to one part of pulp, and the caustic washed out with water after a short period of time which may vary from several seconds to 30 minutes. The pulp thus treated is then made into a paper felt in the usual way. The fibres of the pulp are intensely cr'nlrled by this method. For the purpose of the present invention, the pulp treated in accordance with the described process is defined as being comprised of artificially crinkled fibres. It is essential that the initial brous material started with be in pulp form, that the caustic be washed out within the short time mentioned, which in practice is a time not appreciably longer than required for the mechanical distribution of the liquor throughout the pulp. The paper produced in accordance with this method has a porosity factor, as determined by the Gurley Densometer, ranging from 0.4 second to 12-seconds. When this paper is impregnated with 40% to latex the resulting products have Elmendorf tearing strengths of from 1000 grame to 2000 grans and high porosity values.

The porosity of the product here described is considerably greater than ordinary blotting paper when inpregnated with enough rubber to impart the necessary strength, the porosity factor of the latter being usually greater than 40 whereas the impregnated sheets made with the artiflcially crinkled fibres have a. perosity factor which is not usually greater than 19 and may be as low as 1. It is to be understood that the Elmendorf tear and Gurley Densometer figures as used herein are based upon a fibre weight of 0.68 pound for an area of 36 x 40 inches.

Among the advantages inherent in the practice of the present invention, there may be mentloned the economy in the manufacture of a spinning roll cover as Compared to their manufacture from leather the absence of waste in cutting due to left over pieces of irregular shape, greater uniformity of thickness, surface smoothness and pliability than is usually found in leather covers. As

contrasted with usual leather substitutes having v a fabric base, the material for the spinnng roll cover made as described herein may be cut di-` agona ly by a sharp knife from face to back and produce a joint which is smooth, easily cemented and which is much superior to that obtained from ordinary coated fabrics.

As many apparent widely difierent embodiments of this invention may be made without departing from the spirit and scope thereof, it is to be understood that we do not limit ourselves to the specific embodiments thereof except as defined in the following claims.

We claim:

1. A methodof making a top spinning roll cover which comprises crinkling cellulose fibres by treating paper pulp with an aqueous caustic solution above 8% concentration based on' sodium hydroxide, washing out the caustic after a short period of time, depositing the fibres in sheet form, impregnating the sheet thus formed with rubber latex, applying a coating which dries to a smooth dry surface, cutting asheet of the impregnated material diagonally at the edges at opposite sides and at opposite ends, cementing the edges together to form the sheet into a cylinder.

2. A fiexible, pliable spinning roll cover comprlsing crinkled paper making fibers filted'into paper and impregnated with 10-50% rubber latex, the impregnated felt being cut at opposite sides to present parallel diagonal edges and possessing sufilcient residual porosity to glue with aqueous glues said diagonal cut edges together when the cover is rolled into cylindrical form, and a smooth dry water-proof top coat over the latex impregnated felt.

3. A flexible, pliable spinning roll cover comprising a felt of crinkled paper making fibers impregnated with lil-50% rubber latex,`said impregnated felt being cut at opposite sides to present parallel diagonal edges, said impregnated felt possessing suflicient residual porosity to glue a with aqueous glues said diagonal cut edges together when the cover is rolled into cylindrical form, and a smooth dry water-proof top coat over the latex impregnated felt, said paper fibers being selected from the class of crinkled fibers consisting of cotton fibers and articially crinkled flbers.

JOHN CHABLES EDT.

FREDERICK MCDOVVELL MCNAIR.

GEORGE LEWIS SCHWARTZ.

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